Polyphenylene host compounds

ABSTRACT

Polyphenylene compounds such as compounds represented by Formula I may be used in electronic devices such as organic light-emitting devices. For example, the compounds may be used as host materials in a light-emitting layer.

BACKGROUND

1. Field of the Invention

The embodiments relate to host compounds for light-emitting layers indevices.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are becoming increasinglyimportant in lighting and display applications. OLEDs may include anemissive or light-emitting layer that includes a host material and alight-emitting component dispersed within the host material. Hostmaterials in OLEDs may have problems with low stability, a highcharge-injection barrier, and imbalanced charge injection and mobility.These potential deficiencies with host materials may contribute to lowefficiency and short lifetime of the devices comprising the hostmaterials.

SUMMARY

Some embodiments include a compound represented by Formula 1:

wherein Cy¹, Cy², Cy³, Cy⁴, and Cy⁵ are independently optionallysubstituted p-phenylene; Cy⁶ is optionally substituted phenyl; Cy⁷ isoptionally substituted phenyl or optionally substituted naphthalenyl,wherein Cy⁶ and Cy⁷ optionally link together to form a third ringcomprising the N to which they are attached; and Cy⁸ is optionallysubstituted 1-phenyl-1H-benzo[d]imidazol-2-yl.

With respect to Formula 1, in some embodiments Cy¹, Cy², Cy³, Cy⁴, andCy⁵ are independently p-phenylene optionally substituted with 1 or 2substituents independently selected from C₁₋₆ alkyl and F; Cy⁶ is phenyloptionally substituted with 1, 2, or 3 substituents independentlyselected from C₁₋₆ alkyl and F; Cy⁷ is naphthalen-1-yl optionallysubstituted with 1, 2, or 3 substituents independently selected fromC₁₋₆ alkyl and F; and Cy⁸ is 1-phenyl-1H-benzo[d]imidazol-2-yloptionally substituted with 1, 2, 3, 4, or 5 substituents independentlyselected from C₁₋₆ alkyl and F.

Some embodiments include optionally substituted penta(para-phenylenyl)compounds, including optionally substituted1-(1-phenyl-1H-benzo[d]imidazol-2-yl)-[4^(e)-phenyl(naphthalen-1-yl)amino]penta(para-phenylenyl);optionally substituted1-(1-phenyl-1H-benzo[d]imidazol-2-yl)-[4^(e)-(carbazol-9-yl)amino]penta(para-phenylenyl);optionally substituted1-(1-phenyl-1H-benzo[d]imidazol-2-yl)-[4^(e)-diphenylamino]penta(para-phenylenyl);optionally substituted1-(1-phenyl-1H-benzo[d]imidazol-2-yl)-[4^(e)-phenyl(naphthalen-2-yl)amino]penta(para-phenylenyl);optionally substituted1-(1-phenyl-1H-benzo[d]imidazol-2-yl)-[4^(e)-di(4-methylphenyl)amino]penta(para-phenylenyl);etc.

Some embodiments include a light-emitting device comprising a compounddescribed herein.

These and other embodiments are described in more detail herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of an embodiment of an OLED comprising acompound disclosed herein.

FIG. 2 is an electroluminescent spectrum of a device comprising acompound disclosed herein.

FIG. 3 is a plot of current density and luminance as a function ofdriving voltage for an embodiment of an OLED comprising a compounddisclosed herein.

FIG. 4 is a plot of current efficiency and power efficiency as afunction of luminance for an embodiment of an OLED comprising a compounddisclosed herein.

DETAILED DESCRIPTION

Unless otherwise indicated, when a compound or chemical structuralfeature such as aryl is referred to as being “optionally substituted,”it is meant that the feature may have no substituent (i.e. beunsubstituted) or may have one or more substituents. A feature that is“substituted” has one or more substituents. The term “substituent” hasthe ordinary meaning known to one of ordinary skill in the art. In someembodiments, the substituent may be an ordinary organic moiety known inthe art, which may have a molecular weight (e.g. the sum of the atomicmasses of the atoms of the substituent) of 15 g/mol to 50 g/mol, 15g/mol to 100 g/mol, 15 g/mol to 200 g/mol, 15 g/mol to 300 g/mol, or 15g/mol to 500 g/mol. In some embodiments, the substituent comprises:0-30, 0-20, 0-10, or 0-5 carbon atoms; and 0-30, 0-20, 0-10, or 0-5heteroatoms independently selected from: N, O, S, Si, F, Cl, Br, or I;provided that the substituent comprises at least one atom selected from:C, N, O, S, Si, F, Cl, Br, or I. Examples of substituents include, butare not limited to, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl,heteroalkynyl, aryl, heteroaryl, hydroxy, alkoxy, aryloxy, acyl,acyloxy, alkylcarboxylate, thiol, alkylthio, cyano, halo, thiocarbonyl,O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido,N-amido, S-sulfonamido, N-sulfonamido, isocyanato, thiocyanato,isothiocyanato, nitro, silyl, sulfenyl, sulfinyl, sulfonyl, haloalkyl,haloalkoxyl, trihalomethanesulfonyl, trihalomethanesulfonamido, amino,etc. In some embodiments, two substituents may combine to form a ring.In some embodiments, a substituent may be a linking group that isattached to two or more structural features, e.g., a substituent can bea linking substituent so that Cy¹, Cy², and the linking substituent(e.g., alkyl, —O—, —NH—, etc.) form a fused tricyclic ring system asdescribed in greater detail herein.

Structures associated with some of the chemical names referred to hereinare depicted below. These structures may be unsubstituted, as shownbelow, or a substituent may independently be in any position normallyoccupied by a hydrogen atom when the structure is unsubstituted.

As used herein the term “alkyl” has the ordinary meaning generallyunderstood in the art, and may include a moiety composed of carbon andhydrogen containing no double or triple bonds. Alkyl may be linearalkyl, branched alkyl, cycloalkyl, or a combination thereof, and in someembodiments, may contain from one to thirty-five carbon atoms. In someembodiments, alkyl may include C₁₋₁₀ linear alkyl, such as methyl(—CH₃), ethyl (—CH₂CH₃), n-propyl (—CH₂CH₂CH₃), n-butyl (—CH₂CH₂CH₂CH₃),n-pentyl (—CH₂CH₂CH₂CH₂CH₃), n-hexyl (—CH₂CH₂CH₂CH₂CH₂CH₃), etc.; C₃₋₁₀branched alkyl, such as C₃H₇ (e.g. iso-propyl), C₄H₉ (e.g. branchedbutyl isomers), C₅H₁₁ (e.g. branched pentyl isomers), C₆H₁₃ (e.g.branched hexyl isomers), C₇H₁₅ (e.g. heptyl isomers), etc.; C₃₋₁₀cycloalkyl, such as C₃H₅ (e.g. cyclopropyl), C₄H₇ (e.g. cyclobutylisomers such as cyclobutyl, methylcyclopropyl, etc.), C₅H₉ (e.g.cyclopentyl isomers such as cyclopentyl, methylcyclobutyl,dimethylcyclopropyl, etc.) C₆H₁₁ (e.g. cyclohexyl isomers), C₇H₁₃ (e.g.cycloheptyl isomers), etc.; and the like. In some embodiments, alkyl maybe a linking group that is attached to two or more structural features,e.g., alkyl may be a linking substituent so that Cy¹, Cy², and thelinking substituent form a fused tricyclic ring system as described ingreater detail below.

As used herein, the term “alkoxy” includes —O-alkyl, such as —OCH₃,—OC₂H₅, —OC₃H₇ (e.g. propoxy isomers such as isopropoxy, n-propoxy,etc.), —OC₄H₉ (e.g. butyoxy isomers), —OC₅H₁₁ (e.g. pentoxy isomers),—OC₆H₁₃ (e.g. hexoxy isomers), —OC₇H₁₅ (e.g. heptoxy isomers), etc.

Formula 1 includes compounds such as those depicted by Formulas 2-24.

With respect to any relevant formula or structural depiction herein,Cy1, Cy2, Cy3, Cy4, and Cy5 may independently be optionally substitutedp-phenylene. Those having ordinary skill in the art will readilyrecognize that the synthesis of compounds having five adjacentp-phenylene moieties presents considerable technical and syntheticdifficulty, with no apparent benefit. Thus, absent the teachingsprovided herein, the tendency of those having ordinary skill in the artis to avoid such a molecular configuration. In some embodiments, if thep-phenylene is substituted, it may have 1, 2, 3, or 4 substituents. Insome embodiments, some or all of the substituents on the p-phenylene mayhave: from 0 to 10 carbon atoms and from 0 to 10 heteroatomsindependently selected from: O, N, S, F, Cl, Br, and I; and/or amolecular weight of 15 g/mol to 500 g/mol. For example, the substituentsmay be C1-10 alkyl, such as CH3, C2H5, C3H7, cyclic C3H5, C4H9, cyclicC4H7, C5H11, cyclic C5H9, C6H13, cyclic C6H11, etc.; C1-10 alkoxy; halo,such as F, Cl, Br, I; OH; CN; NO2; C1-6 fluoroalkyl, such as CF3, CF2H,C2F5, etc.; a C1-10 ester such as —O2CCH3, —CO2CH3, —O2CC2H5, —CO2C2H5,—O2C-phenyl, —OC2-phenyl, etc.; a C1-10 ketone such as —COCH3, —COC2H5,—COC3H7, —CO-phenyl, etc.; or a C1-10 amine such as NH2, NH(CH3),N(CH3)2, N(CH3)C2H5, etc. In some embodiments, the p-phenylene isoptionally substituted with 1 or 2 substituents independently selectedfrom C₁₋₆ alkyl and F.

In some embodiments, Cy¹ may be:

In some embodiments, Cy¹ is unsubstituted.

In some embodiments, Cy² may be:

In some embodiments, Cy² is unsubstituted.

With respect to any relevant formula or structural feature above, suchas Formulas 1, 2, 3, 4, 5, 6, 7, 8, 9, 13, 15, 16, 17, 18, and 19, insome embodiments Cy¹ and Cy² are unsubstituted.

In some embodiments, Cy¹ and Cy² may share a linking substituent so thatCy¹, Cy², and the linking substituent form a fused tricyclic ringsystem. For example, -Cy¹-Cy²- may be:

With respect to any relevant formula or structural depiction above, X¹may be any substituent that links Cy¹ to Cy². In some embodiments, thesubstituent that that links Cy¹ to Cy² may have: from 0 to 15 carbonatoms and from 0 to 10 heteroatoms independently selected from: O, N, S,F, Cl, Br, and I; and/or a molecular weight of 15 g/mol to 500 g/mol.

In some embodiments, X¹ may be:

—O—, or —S—.

In some embodiments, X¹ may be:

In some embodiments, Cy³ may be:

In some embodiments, Cy³ is unsubstituted.

In some embodiments, Cy² and Cy³ may share a linking substituent so thatCy², Cy³, and the linking substituent form a fused tricyclic ringsystem. For example, -Cy²-Cy³- may be:

With respect to any relevant formula or structural depiction above, X²may be any substituent that links Cy² to Cy³. In some embodiments, thesubstituent that that links Cy² to Cy³ may have: from 0 to 15 carbonatoms and from 0 to 10 heteroatoms independently selected from: O, N, S,F, Cl, Br, and I; and/or a molecular weight of 15 g/mol to 500 g/mol.

In some embodiments, X² may be:

—O—, or —S—.

In some embodiments, X² may be:

In some embodiments, Cy⁴ may be:

In some embodiments, Cy⁴ is unsubstituted.

With respect to any relevant formula or structural feature above, suchas Formulas 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 17, and 19, in someembodiments Cy³ and Cy⁴ are unsubstituted.

In some embodiments, Cy³ and Cy⁴ may share a linking substituent so thatCy³, Cy⁴, and the linking substituent form a fused tricyclic ringsystem. For example, -Cy³-Cy⁴- may be:

With respect to any relevant formula or structural depiction above, X³may be any substituent that links Cy³ to Cy⁴. In some embodiments, thesubstituent that that links Cy³ to Cy⁴ may have: from 0 to 15 carbonatoms and from 0 to 10 heteroatoms independently selected from: O, N, S,F, Cl, Br, and I; and/or a molecular weight of 15 g/mol to 500 g/mol.

In some embodiments, X³ may be:

—O—, or —S—.

In some embodiments, X³ may be:

In some embodiments, Cy⁵ may be:

In some embodiments, Cy⁵ is unsubstituted.

In some embodiments, Cy⁴ and Cy⁵ may share a linking substituent so thatCy⁴, Cy⁵, and the linking substituent form a fused tricyclic ringsystem. For example, -Cy⁴-Cy⁵- may be:

With respect to any relevant formula or structural depiction above, X⁴may be any substituent that links Cy⁴ to Cy⁵. In some embodiments, thesubstituent that that links Cy⁴ to Cy⁵ may have: from 0 to 15 carbonatoms and from 0 to 10 heteroatoms independently selected from: O, N, S,F, Cl, Br, and I; and/or a molecular weight of 15 g/mol to 500 g/mol.

In some embodiments, X⁴ may be:

—O—, or —S—.

In some embodiments, X⁴ may be:

With respect to any relevant formula or structural depiction above, Cy⁶may be optionally substituted phenyl. In some embodiments, if the phenylis substituted, it may have 1, 2, 3, 4, or 5 substituents. Anysubstituent may be included on the phenyl. In some embodiments, some orall of the substituents on the phenyl may have: from 0 to 15 carbonatoms and from 0 to 10 heteroatoms independently selected from: O, N, S,F, Cl, Br, and I; and/or a molecular weight of 15 g/mol to 500 g/mol.For example, the substituents may be C₁₋₁₀ alkyl, such as CH₃, C₂H₅,C₃H₇, cyclic C₃H₅, C₄H₉, cyclic C₄H₇, C₅H₁₁, cyclic C₅H₉, C₆H₁₃, cyclicC₆H₁₁, etc.; C₁₋₁₀ alkoxy; halo, such as F, Cl, Br, I; OH; CN; NO₂; C₁₋₆fluoroalkyl, such as CF₃, CF₂H, C₂F₅, etc.; a C₁₋₁₀ ester such as—O₂CCH₃, —CO₂CH₃, —O₂CC₂H₅, —CO₂C₂H₅, —O₂C-phenyl, —CO₂-phenyl, etc.; aC₁₋₁₀ ketone such as —COCH₃, —COC₂H₅, —COC₃H₇, —CO-phenyl, etc.; or aC₁₋₁₀ amine such as NH₂, NH(CH₃), N(CH₃)₂, N(CH₃)C₂H₅, NH-phenyl, etc.In some embodiments, the phenyl is optionally substituted with 1, 2, or3 substituents independently selected from C₁₋₆ alkyl and F. In someembodiments, Cy⁶ is unsubstituted.

In some embodiments, Cy⁶ may be:

With respect to any relevant formula or structural depiction above, Cy⁷may be optionally substituted phenyl or optionally substitutednaphthalenyl, wherein Cy⁶ and Cy⁷ may optionally link together to form afused tricyclic ring system comprising N. In some embodiments, if thephenyl is substituted, it may have 1, 2, 3, 4, or 5 substituents. Insome embodiments, if the naphthalenyl is substituted, it may have 1, 2,3, 4, 5, 6, or 7 substituents. Any substituent may be included on thephenyl or the naphthalenyl. In some embodiments, some or all of thesubstituents on the phenyl or the naphthalenyl may have: from 0 to 15carbon atoms and from 0 to 10 heteroatoms independently selected from:O, N, S, F, Cl, Br, and I; and/or a molecular weight of 15 g/mol to 500g/mol. For example, the substituents may be C₁₋₁₀ alkyl, such as CH₃,C₂H₅, C₃H₇, cyclic C₃H₅, C₄H₉, cyclic C₄H₇, C₅H₁₁, cyclic C₅H₉, C₆H₁₃,cyclic C₆H₁₁, etc.; C₁₋₁₀ alkoxy; halo, such as F, Cl, Br, I; OH; CN;NO₂; C₁₋₆ fluoroalkyl, such as CF₃, CF₂H, C₂F₅, etc.; a C₁₋₁₀ ester suchas —O₂CCH₃, —CO₂CH₃, —O₂CC₂H₅, —CO₂C₂H₅, —O₂C-phenyl, —CO₂-phenyl, etc.;a C₁₋₁₀ ketone such as —COCH₃, —COC₂H₅, —COC₃H₇, —CO-phenyl, etc.; or aC₁₋₁₀ amine such as NH₂, NH(CH₃), N(CH₃)₂, N(CH₃)C₂H₅, etc. In someembodiments, the phenyl or the naphthalenyl is optionally substitutedwith 1, 2, or 3 substituents independently selected from C₁₋₆ alkyl andF. In some embodiments, Cy⁷ is unsubstituted.

In some embodiments, Cy⁷ may be:

In some embodiments,

may be:

With respect to any relevant formula or structural feature above, suchas Formulas 1, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19, in someembodiments Cy⁶ and Cy⁷ are unsubstituted.

With respect to any relevant formula or structural depiction above, Cy⁸may be optionally substituted 1-phenyl-1H-benzo[d]imidazol-2-yl. In someembodiments, if the 1-phenyl-1H-benzo[d]imidazol-2-yl is substituted, itmay have 1, 2, 3, 4, 5, 6, 7, 8, or 9 substituents. Any substituent maybe included. In some embodiments, some or all of the substituents on thephenyl may have: from 0 to 10 carbon atoms and from 0 to 10 heteroatomsindependently selected from: O, N, S, F, Cl, Br, and I; and/or amolecular weight of 15 g/mol to 500 g/mol. For example, the substituentsmay be C₁₋₁₀ alkyl, such as CH₃, C₂H₅, C₃H₇, cyclic C₃H₅, C₄H₉, cyclicC₄H₇, C₅H₁₁, cyclic C₅H₉, C₆H₁₃, cyclic C₆H₁₁, etc.; C₁₋₁₀ alkoxy; halo,such as F, Cl, Br, I; OH; CN; NO₂; C₁₋₆ fluoroalkyl, such as CF₃, CF₂H,C₂F₅, etc.; a C₁₋₁₀ ester such as —O₂CCH₃, —CO₂CH₃, —O₂CC₂H₅, —CO₂C₂H₅,—O₂C-phenyl, —CO₂-phenyl, etc.; a C₁₋₁₀ ketone such as —COCH₃, —COC₂H₅,—COC₃H₇, —CO-phenyl, etc.; or a C₁₋₁₀ amine such as NH₂, NH(CH₃),N(CH₃)₂, N(CH₃)C₂H₅, etc. In some embodiments, Cy⁸ is optionallysubstituted with 1, 2, or 3 substituents independently selected fromC₁₋₆ alkyl and F. In some embodiments, Cy⁸ is unsubstituted.

In some embodiments, Cy⁸ may be:

With respect to any relevant formula or structural feature above, suchas Formulas 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 13, 14, 15, and 16, insome embodiments Cy⁵ and Cy⁸ are unsubstituted.

With respect to any relevant formula or structural depiction herein,each R^(A) may independently be H; phenyl optionally substituted with 1,2, 3, 4, or 5 substituents selected from: C₁₋₃ alkyl, halo, OH, or C₁₋₃alkoxy; or C₁₋₁₂ alkyl, including: linear or branched alkyl having aformula C_(a)H_(2a+1), wherein a is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,or 12, such as: CH₃, C₂H₅, C₃H₇, C₄H₉, C₅H₁₁, C₆H₁₃, C₇H₁₅, C₈H₁₇,C₉H₁₉, C₁₀H₂₁, etc., or cycloalkyl having a formula C_(b)H_(2b−1),wherein b is 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, such as: C₃H₅, C₄H₇,C₅H₉, C₆H₁₁, C₇H₁₃, C₈H₁₅, C₉H₁₇, C₁₀H₁₉, etc.

With respect to any relevant formula or structural depiction above, eachR^(B) may independently be H; phenyl optionally substituted with 1, 2,3, 4, or 5 substituents selected from: C₁₋₃ alkyl, halo, OH, or C₁₋₃alkoxy; or C₁₋₁₂ alkyl, including: linear or branched alkyl having aformula C_(a)H_(2a+1), wherein a is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,or 12, such as: CH₃, C₂H₅, C₃H₇, C₄H₉, C₅H₁₁, C₆H₁₃, C₇H₁₅, C₈H₁₇,C₉H₁₉, C₁₀H₂₁, etc., or cycloalkyl having a formula C_(b)H_(2b−1),wherein b is 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, such as: C₃H₅, C₄H₇,C₅H₉, C₆H₁₁, C₇H₁₃, C₈H₁₅, C₉H₁₇, C₁₀H₁₉, etc.

With respect to any relevant formula or structural depiction above, R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷,R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹, R³⁰, R³¹,R³², R³³, R³⁴, R³⁵, R³⁶, R³⁷, R³⁸, R³⁹, and R⁴¹ (“R¹⁻⁴¹”) mayindependently be H or any substituent, such as a substituent having from0 to 6 carbon atoms and from 0 to 5 heteroatoms independently selectedfrom: O, N, S, F, Cl, Br, and I, wherein the substituent has a molecularweight of 15 g/mol to 300 g/mol. Some non-limiting examples of any ofR¹⁻⁴¹ may independently include R^(A), F, Cl, CN, OR^(A), CF₃, NO₂,NR^(A)R^(B), COR^(A), CO₂R^(A), OCOR^(A), etc. In some embodiments, anyof R¹⁻⁴¹ may independently be H, C₁₋₆ alkyl, such as methyl, ethyl,propyl isomers, cyclopropyl, butyl isomers, cyclobutyl isomers, pentylisomers, cyclopentyl isomers, hexyl isomers, cyclohexyl isomers, etc.,or C₁₋₆ alkoxy, such as —O-methyl, —O-ethyl, isomers of —O-propyl,—O-cyclopropyl, isomers of —O-butyl, isomers of —O-cyclobutyl, isomersof —O-pentyl, isomers of —O-cyclopentyl, isomers of —O-hexyl, isomers of—O-cyclohexyl, etc. In some embodiments, any of R¹⁻⁴¹ may independentlybe H, F, methyl, ethyl, propyl, or isopropyl. In some embodiments, anyof R¹⁻⁴¹ may be H. In some embodiments, any of R¹⁻⁴¹ may independentlybe a linking group that is attached to two or more structural features,e.g., any of R¹⁻⁴¹ may be a linking substituent so that Cy¹, Cy², andthe linking substituent form a fused tricyclic ring system as describedin greater detail herein.

With respect to any relevant formula or structural feature above, suchas Formulas 2, 3, 6, 7, 20, 21, and 22 in some embodiments R¹, R², R³,R⁴, and R⁵ are independently H, F, methyl, ethyl, propyl, or isopropyl.In some embodiments R¹, R², R³, R⁴, and R⁵ are H.

With respect to any relevant formula or structural feature above, suchas Formulas 4 and 23, in some embodiments R¹, R², R⁴, and R⁵ areindependently H, F, methyl, ethyl, propyl, or isopropyl. In someembodiments R¹, R², R⁴, and R⁵ are H.

With respect to any relevant formula or structural feature above, suchas Formulas 6, 7, 8, 9, 20, and 21, in some embodiments R⁶, R⁷, R⁸, R⁹,R¹⁰, R¹¹, and R¹² are independently H, F, methyl, ethyl, propyl, orisopropyl. In some embodiments R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, and R¹² are H.

With respect to any relevant formula or structural feature above, suchas Formulas 6, 7, 20, and 21, in some embodiments, R¹, R², R³, R⁴, R⁵,R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, and R¹² are independently H, F, methyl, ethyl,propyl, or isopropyl. In some embodiments R¹, R², R³, R⁴, R⁵, R⁶, R⁷,R⁸, R⁹, R¹⁰, R¹¹, and R¹² are H.

With respect to any relevant formula or structural feature above, suchas Formulas 3 and 22, in some embodiments R¹, R², R³, R⁴, R⁶, R⁷, R⁸,R⁹, and R¹⁰ are independently H, F, methyl, ethyl, propyl, or isopropyl.In some embodiments R¹, R², R³, R⁴, R⁶, R⁷, R⁸, R⁹, and R¹⁰ are H.

With respect to any relevant formula or structural feature above, suchas Formulas 10, 20, 21, 22, 23, and 24, in some embodiments R¹³, R¹⁴,R¹⁵, and R¹⁶ are independently H, F, methyl, ethyl, propyl, orisopropyl. In some embodiments R¹³, R¹⁴, R¹⁵, and R¹⁶ are H.

With respect to any relevant formula or structural feature above, suchas Formulas 11, 20, 21, 22, 23, and 24, in some embodiments R¹⁷, R¹⁸,R¹⁹, and R²⁰ are independently H, F, methyl, ethyl, propyl, orisopropyl. In some embodiments R¹⁷, R¹⁸, R¹⁹, and R²⁰ are H

With respect to any relevant formula or structural feature above, suchas Formulas 13, 20, 21, 22, 23, and 24, in some embodiments, R²¹, R²²,R²³, and R²⁴ are independently H, F, methyl, ethyl, propyl, orisopropyl. In some embodiments R²¹, R²², R²³, and R²⁴ are H.

With respect to any relevant formula or structural feature above, suchas Formulas 15, 20, 21, 22, 23, and 24, in some embodiments R²⁵, R²⁶,R²⁷, and R²⁸ are independently H, F, methyl, ethyl, propyl, orisopropyl. In some embodiments R²⁵, R²⁶, R²⁷, and R²⁸ are H.

With respect to any relevant formula or structural feature above, suchas Formulas 17, 20, 21, 22, 23, and 24, in some embodiments R²⁹, R³⁰,R³¹, and R³² are independently H, F, methyl, ethyl, propyl, orisopropyl. In some embodiments R²⁹, R³⁰, R³¹, and R³² are H.

With respect to any relevant formula or structural feature above, suchas Formulas 19, 20, 21, 22, 23, and 24, in some embodiments R³³, R³⁴,R³⁵, R³⁶, R³⁷, R³⁸, R³⁹, R⁴⁰, and R⁴¹ are independently H, F, methyl,ethyl, propyl, or isopropyl. In some embodiments R³³, R³⁴, R³⁵, R³⁶,R³⁷, R³⁸, R³⁹, R⁴⁰, and R⁴¹ are H.

Some embodiments may include one of the compounds below:

Some embodiments include a composition comprising a compound of any oneof Formulas 1-24 or any specific compound depicted or named herein(hereinafter referred to as “a subject compound”). A compositioncomprising a subject compound may further comprise a fluorescentcompound or a phosphorescent compound, and may be useful for lightemission in devices such as organic light-emitting devices.

In some embodiments, an organic light-emitting device comprises asubject compound. For example, light-emitting layer comprising a subjectcompound may is disposed between an anode and a cathode. The device isconfigured so that electrons can be transferred from the cathode to thelight-emitting layer and holes can be transferred from the anode to thelight-emitting layer.

The subject compounds may have high photostability and thermal stabilityin organic light-emitting devices. The subject compounds may also havewell balanced hole and electron injection rates and mobilities. This mayprovide OLED devices with high efficiencies and/or long lifetimes. Thesubject compounds may also form amorphous solids, which may make thecompounds easy to form into films.

The anode may be a layer comprising a conventional material such as ametal, mixed metal, alloy, metal oxide or mixed-metal oxide, conductivepolymer, and/or an inorganic material such as carbon nanotube (CNT).Examples of suitable metals include the Group 1 metals, the metals inGroups 4, 5, 6, and the Group 8-10 transition metals. If the anode layeris to be light-transmitting, metals in Group 10 and 11, such as Au, Pt,and Ag, or alloys thereof; or mixed-metal oxides of Group 12, 13, and 14metals, such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), and thelike, may be used. In some embodiments, the anode layer may be anorganic material such as polyaniline. The use of polyaniline isdescribed in “Flexible light-emitting diodes made from solubleconducting polymer,” Nature, vol. 357, pp. 477-479 (11 Jun. 1992). Insome embodiments, the anode layer can have a thickness in the range ofabout 1 nm to about 1000 nm.

A cathode may be a layer including a material having a lower workfunction than the anode layer. Examples of suitable materials for thecathode layer include those selected from alkali metals of Group 1,Group 2 metals, Group 12 metals including rare earth elements,lanthanides and actinides, materials such as aluminum, indium, calcium,barium, samarium and magnesium, and combinations thereof. Li-containingorganometallic compounds, LiF, and Li₂O may also be deposited betweenthe organic layer and the cathode layer to lower the operating voltage.Suitable low work function metals include but are not limited to Al, Ag,Mg, Ca, Cu, Mg/Ag, LiF/Al, CsF, CsF/Al or alloys thereof. In someembodiments, the cathode layer can have a thickness in the range ofabout 1 nm to about 1000 nm.

In some embodiments, a light-emitting layer may comprise alight-emitting component and a subject compound as a host. The amount ofthe host in a light-emitting layer may vary. In one embodiment, theamount of a host in a light-emitting layer is in the range of from about1% to about 99.9% by weight of the light-emitting layer. In anotherembodiment, the amount of a host in a light-emitting layer is in therange of from about 90% to about 99% by weight of the light-emittinglayer. In another embodiment, the amount of a host in a light-emittinglayer is about 97% by weight of the light-emitting layer. In someembodiments, the mass of the light-emitting component is about 0.1% toabout 10%, about 1% to about 5%, or about 3% of the mass of thelight-emitting layer. The light-emitting component may be a fluorescentand/or a phosphorescent compound.

A light-emitting component may comprise an iridium coordination compoundsuch as:bis-{2-[3,5-bis(trifluoromethyl)phenyl]pyridinato-N,C2′}iridium(III)-picolinate;bis(2-[4,6-difluorophenyl]pyridinato-N,C2′)iridium(III) picolinate;bis(2-[4,6-difluorophenyl]pyridinato-N,C2′)iridium(acetylacetonate);Iridium (III)bis(4,6-difluorophenylpyridinato)-3-(trifluoromethyl)-5-(pyridine-2-yl)-1,2,4-triazolate;Iridium (III)bis(4,6-difluorophenylpyridinato)-5-(pyridine-2-yl)-1H-tetrazolate;bis[2-(4,6-difluorophenyl)pyridinato-N,C^(2′)]iridium(III)tetra(1-pyrazolyl)borate;Bis[2-(2′-benzothienyl)-pyridinato-N,C3′]iridium(III)(acetylacetonate);Bis[(2-phenylquinolyl)-N,C2′]iridium(III) (acetylacetonate);Bis[(1-phenylisoquinolinato-N,C2′)]iridium(III) (acetylacetonate);Bis[(dibenzo[f,h]quinoxalino-N,C2′)iridium(III)(acetylacetonate);Tris(2,5-bis-2′-(9′,9′-dihexylfluorene)pyridine)iridium(III);Tris[1-phenylisoquinolinato-N,C2′]iridium(III);Tris-[2-(2′-benzothienyl)-pyridinato-N,C3′]iridium(III);Tris[1-thiophen-2-ylisoquinolinato-N,C3′]iridium(III);Tris[1-(9,9-dimethyl-9H-fluoren-2-yl)isoquinolinato-(N,C3′)iridium(III)); Bis(2-phenylpyridinato-N,C2′)iridium(III)(acetylacetonate)[Ir(ppy)₂(acac)];Bis(2-(4-tolyl)pyridinato-N,C2′)iridium(III)(acetylacetonate)[Ir(mppy)₂(acac)];Bis(2-(4-tert-butyl)pyridinato-N,C2′)iridium(III)(acetylacetonate)[Ir(t-Buppy)₂(acac)]; Tris(2-phenylpyridinato-N,C2′)iridium(III)[Ir(ppy)₃]; Bis(2-phenyloxazolinato-N,C2′)iridium(III) (acetylacetonate)[Ir(op)₂(acac)]; Tris(2-(4-tolyl)pyridinato-N,C2′)iridium(III)[Ir(mppy)₃]; Bis[2-phenylbenzothiazolato-N,C2′]iridium(III)(acetylacetonate);Bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2′]iridium(III)(acetylacetonate);Bis[(2-(2′-thienyl)pyridinato-N,C3′)]iridium(III) (acetylacetonate);Tris[2-(9.9-dimethylfluoren-2-yl)pyridinato-(N,C3′)]iridium(III);Tris[2-(9.9-dimethylfluoren-2-yl)pyridinato-(N,C3′)]iridium(III);Bis[5-trifluoromethyl-2-[3-(N-phenylcarbzolyl)pyridinato-N,C2′]iridium(III)(acetylacetonate);(2-PhPyCz)₂Ir(III)(acac); etc.

The thickness of a light-emitting layer may vary. In one embodiment, alight-emitting layer has a thickness in the range of from about 1 nm toabout 150 nm or about 200 nm.

Some embodiments may have a structure as represented schematically byFIG. 1. A light-emitting layer 20 is disposed between an anode 5 andcathode 35. An optional electron-transport layer 30 may be disposedbetween the light-emitting layer 20 and the cathode 35. An optionalhole-injection layer 10 may be disposed between the light-emitting layer20 and the anode 5, and an optional hole-transport layer 15 may bedisposed between the hole-injecting layer 10 and the light-emittinglayer 20.

A hole-transport layer may comprise at least one hole-transportmaterial. Hole-transport materials may include, but are not limited to,an aromatic-substituted amine, a carbazole, a polyvinylcarbazole (PVK),e.g. poly(9-vinylcarbazole); polyfluorene; a polyfluorene copolymer;poly(9,9-di-n-octylfluorene-alt-benzothiadiazole); poly(paraphenylene);poly[2-(5-cyano-5-methylhexyloxy)-1,4-phenylene]; a benzidine; aphenylenediamine; a phthalocyanine metal complex; a polyacetylene; apolythiophene; a triphenylamine; an oxadiazole; copper phthalocyanine;1,1-Bis(4-bis(4-methylphenyl)aminophenyl)cyclohexane;2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline;3,5-Bis(4-tert-butyl-phenyl)-4-phenyl[1,2,4]triazole;3,4,5-Triphenyl-1,2,3-triazole;4,4′,4′-tris(3-methylphenylphenylamino)triphenylamine (MTDATA);N,N′-bis(3-methylphenyl)N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(TPD); 4,4′-bis[N-(naphthalenyl)-N-phenyl-amino]biphenyl (α-NPD);4,4′,4″-tris(carbazol-9-yl)-triphenylamine (TCTA);4,4′-bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD);4,4′-N,N′-dicarbazole-biphenyl (CBP); 1,3-N,N-dicarbazole-benzene (mCP);Bis[4-(p,p′-ditolyl-amino)phenyl]diphenylsilane (DTASi);2,2′-bis(4-carbazolylphenyl)-1,1′-biphenyl (4CzPBP);N,N′N″-1,3,5-tricarbazoloylbenzene (tCP);N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine; or the like.

A hole-injecting layer may comprise any suitable hole-injectingmaterial. Examples of suitable hole-injecting material(s) include, butare not limited to, an optionally substituted compound selected from thefollowing: molybdenum oxide (MoO₃), a polythiophene derivative such aspoly(3,4-ethylenedioxythiophene (PEDOT)/polystyrene sulphonic acid(PSS), a benzidine derivative such as N,N,N′,N′-tetraphenylbenzidine,poly(N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine), a triphenylamine or phenylenediamine derivative such asN,N′-bis(4-methylphenyl)-N,N′-bis(phenyl)-1,4-phenylenediamine,4,4′,4″-tris(N-(naphthalen-2-yl)-N-phenylamino)triphenylamine, anoxadiazole derivative such as1,3-bis(5-(4-diphenylamino)phenyl-1,3,4-oxadiazol-2-yl)benzene, apolyacetylene derivative such as poly(1,2-bis-benzylthio-acetylene), anda phthalocyanine metal complex derivative such as phthalocyanine copper.

An electron-transport layer may comprise at least one electron-transportmaterial. Examples of electron-transport materials may include, but arenot limited to, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole(PBD); 1,3-bis(N,N-t-butyl-phenyl)-1,3,4-oxadiazole (OXD-7),1,3-bis[2-(2,2′-bipyridine-6-yl)-1,3,4-oxadiazo-5-yl]benzene;3-phenyl-4-(1′-naphthalenyl)-5-phenyl-1,2,4-triazole (TAZ);2,9-dimethyl-4,7-diphenyl-phenanthroline (bathocuproine or BCP);aluminum tris(8-hydroxyquinolate) (Alq3); and1,3,5-tris(2-N-phenylbenzimidazolyl)benzene;1,3-bis[2-(2,2′-bipyridine-6-yl)-1,3,4-oxadiazo-5-yl]benzene (BPY-OXD);3-phenyl-4-(1′-naphthalenyl)-5-phenyl-1,2,4-triazole (TAZ),2,9-dimethyl-4,7-diphenyl-phenanthroline (bathocuproine or BCP); and1,3,5-tris[2-N-phenylbenzimidazol-z-yl]benzene (TPBI). In oneembodiment, the electron-transport layer is aluminum quinolate (Alq₃),2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD),phenanthroline, quinoxaline,1,3,5-tris[N-phenylbenzimidazol-z-yl]benzene (TPBI), or a derivative ora combination thereof.

If desired, additional layers may be included in the light-emittingdevice. These additional layers may include an electron injecting layer(EIL) between the cathode and the light-emitting layer, a hole-blockinglayer (HBL) between the anode and the light-emitting layer, and/or anexciton-blocking layer (EBL) between the light-emitting layer and theanode and/or the cathode. In addition to separate layers, some of thesematerials may be combined into a single layer.

In some embodiments, the light-emitting device can include anelectron-injecting layer between the cathode layer and thelight-emitting layer. Examples of suitable material(s) that can beincluded in the electron injecting layer include but are not limited to,an optionally substituted compound selected from the following: lithiumfluoride (LiF), aluminum quinolate (Alq₃),2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD),phenanthroline, quinoxaline,1,3,5-tris[N-phenylbenzimidazol-z-yl]benzene (TPBI) a triazine, a metalchelate of 8-hydroxyquinoline such as tris(8-hydroxyquinoliate)aluminum, and a metal thioxinoid compound such asbis(8-quinolinethiolato) zinc. In one embodiment, the electron injectinglayer is aluminum quinolate (Alq₃),2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD),phenanthroline, quinoxaline,1,3,5-tris[N-phenylbenzimidazol-z-yl]benzene (TPBI), or a derivative ora combination thereof.

In some embodiments, the device can include a hole-blocking layer, e.g.,between the cathode and the light-emitting layer. Various suitablehole-blocking materials that can be included in the hole-blocking layerare known to those skilled in the art. Suitable hole-blockingmaterial(s) include but are not limited to, an optionally substitutedcompound selected from the following: bathocuproine (BCP),3,4,5-triphenyl-1,2,4-triazole,3,5-bis(4-tert-butyl-phenyl)-4-phenyl-[1,2,4]triazole,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and1,1-bis(4-bis(4-methylphenyl)aminophenyl)-cyclohexane.

In some embodiments, the light-emitting device can include anexciton-blocking layer, e.g., between the light-emitting layer and theanode. In an embodiment, the band gap of the material(s) that compriseexciton-blocking layer is large enough to substantially prevent thediffusion of excitons. A number of suitable exciton-blocking materialsthat can be included in the exciton-blocking layer are known to thoseskilled in the art. Examples of material(s) that can compose anexciton-blocking layer include an optionally substituted compoundselected from the following: aluminum quinolate (Alq₃),4,4′-bis[N-(naphthalenyl)-N-phenyl-amino]biphenyl (α-NPD),4,4′-N,N′-dicarbazole-biphenyl (CBP), and bathocuproine (BCP), and anyother material(s) that have a large enough band gap to substantiallyprevent the diffusion of excitons.

Light-emitting devices comprising a subject compound can be fabricatedusing techniques known in the art, as informed by the guidance providedherein. For example, a glass substrate can be coated with a high workfunctioning metal such as ITO which can act as an anode. Afterpatterning the anode layer, a light-emitting layer comprising alight-emitting component, can be deposited on the anode. In someembodiments, additional optional layers such as a hole-transport layer,a hole-injecting layer, and/or an exciton-blocking layer may bedeposited between the light-emitting layer and the anode, by methodssuch as vapor deposition, sputtering, or spin coating. The cathodelayer, comprising a low work functioning metal (e.g., Mg:Ag), can thenbe deposited on the light-emitting layer, e.g., by vapor deposition,sputtering, or spin coating. In some embodiments, additional optionallayers such as an electron-transport layer, an electron-injection layer,and/or an exciton-blocking layer, can be added to the device usingsuitable techniques such as vapor deposition, sputtering, or spincoating.

In some embodiments, a device comprising the subject compounds canprovide a significantly increased device lifetime compared withcommercially available compounds. In some embodiments, the devices canprovide a T50(h) @ 10000 nit lifetime of at least about 125 hours, 150hours, 175 hours, 185 hours, and/or 200 hours. In some embodiments, thedesired lifetime can be determined by examining the luminescent/emissivedecay of the device by measuring the luminescent, e.g., in cd/m², afterapplying a constant current of a 106 mA to device (corresponding toabout 10000 cd/m²) for a device having an active emissive surface areaof about 13.2 mm².

Synthetic Examples Example 1.1

Example 1.1.1

4-Bromo-N-(2-(phenylamino)phenyl)benzamide (1)

To a solution of 4-bromo-benzoyl chloride (11 g, 50 mmol) in anhydrousdichloromethane (DCM) (100 ml), was added N-phenylbenzene-1,2-diamine(10.2 g, 55 mmol), then triethylamine (TEA) (17 ml, 122 mmol) slowly.The whole was stirred at room temperature (RT) overnight. Filtrationgave a white solid 1 (6.5 g). The filtrate was worked up with water (300ml), then extracted with DCM (300 ml) three times. The organic phase wascollected and dried over MgSO4, concentrated and recrystallized inDCM/hexanes to give another portion of white solid 1 (10.6 g). Totalamount of product 1 is 17.1 g, in 93% yield.

Example 1.1.2

2-(4-bromophenyl)-1-phenyl-1H-benzo[d]imidazole (2)

To a suspension of amide 1 (9.6 g, 26 mmol) in anhydrous 1,4-dioxane(100 mL) was added phosphorus oxychloride (POCl₃) (9.2 mL, 100 mmol)slowly. The whole was then heated at 100° C. overnight. After cooling toRT, the mixture was poured into ice (200 g) with stirring. Filtration,followed by recrystallization in DCM/hexanes gave a pale grey solid 2(8.2 g, in 90% yield).

Example 1.1.3

1-phenyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1H-benzo[d]imidazole(3)

A mixture of Compound 2 (0.70 g, 2 mmol), bis(pinacolate)diborane (0.533g, 2.1 mmol), bis(diphenylphosphino)ferrocene]dichloropalladium(Pd(dppf)Cl₂) (0.060 g, 0.08 mmol) and anhydrous potassium acetate(KOAc) (0.393 g, 4 mmol) in 1,4-dioxane (20 ml) was heated at 80° C.under argon overnight. After cooling to RT, the whole was diluted withethyl acetate (80 ml) then filtered. The solution was absorbed on silicagel, then purified by column chromatography (hexanes/ethyl acetate 5:1to 3:1) to give a white solid 3 (0.64 g, in 81% yield).

Example 1.1.3

2-(4′-bromo-[1,1′-biphenyl]-4-yl)-1-phenyl-1H-benzo[d]imidazole (4)

A mixture of compound 3 (4.01 g, 10.1 mmol), 1-bromo-4-iodobenzene (5.73g, 20.2 mmol), Pd(PPh₃)₄ (0.58 g, 0.5 mmol) and potassium carbonate (4.2g, 30 mmol) in dioxane/water (60 ml/10 ml) was degassed and heated at95° C. overnight. After being cooled to RT, the mixture was poured intoethyl acetate (250 ml), washed with brine, dried over Na₂SO₄, thenloaded on silica gel, purified by flash column (hexanes to hexanes/ethylacetate 4:1) to give a light yellow solid washed with methanol and driedin air (3.39 g, in 80% yield).

Example 1.1.4

1-phenyl-2-(4′-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′-biphenyl]-4-yl)-1H-benzo[d]imidazole(5)

A mixture of Compound 4 (1.2 g, 2.82 mmol), bis(pinacolate)diborane(0.72 g, 2.82 mmol), bis(diphenylphosphino)ferrocene]dichloropalladium(Pd(dppf)Cl₂) (0.10 g, 0.14 mmol) and anhydrous potassium acetate (KOAc)(2.0 g, 20 mmol) in 1,4-dioxane (45 ml) was heated at 80° C. under argonovernight. After cooling to RT, the whole was diluted with ethyl acetate(150 ml) then filtered. The solution was absorbed on silica gel, thenpurified by column chromatography (hexanes/ethyl acetate 5:1 to 3:1) togive a white solid 5 (1.14 g, in 86% yield).

Example 1.2

Example 1.2.1

N-(4′-bromo-[1,1′-biphenyl]-4-yl)-N-phenylnaphthalen-1-amine (6)

A mixture of N-phenylnaphthalen-1-amine (4.41 g, 20 mmol),4,4′-dibromo-1,1′-biphenyl (15 g, 48 mmol), sodium tert-butoxide (4.8 g,50 mmol) and Pd(dppf)Cl₂ (0.44 g, 0.6 mmol) in anhydrous toluene (100ml) was degassed and heated at 80° C. for 10 hours. After cooling to RT,the mixture was poured into dichloromethane (400 ml) and stirred for 30min, then washed with brine (100 ml). The organic is collected and driedover Na₂SO₄, loaded on silica gel, and purified by flash column (hexanesto hexanes/ethyl acetate 90:1) to give a solid which was washed withmethanol and dried under air to give a white solid 4 (5.58 g, in 62%yield).

Example 1.2.2

N-phenyl-N-(4′-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′-biphenyl]-4-yl)naphthalen-1-amine(7)

A mixture of Compound 6 (5.5 g, 12.2 mmol), bis(pinacolate)diborane(3.10 g, 12.2 mmol), Pd(dppf)Cl₂ (0.446 mg, 0.6 mmol) and KOAc (5.5 g,56 mmol) in anhydrous dioxane (60 ml) was degassed and heated at 80° C.overnight. After being cooled to RT, the mixture was poured into ethylacetate (200 ml), washed with brine (150 ml). The organic solution wasdried over Na₂SO₄, loaded on silica gel and purified by flash column(hexanes to hexanes/ethyl acetate 30:1) to collect the major fraction.After removal of solvent, the solid was washed with methanol, filteredand dried in air to give a white solid 7 (5.50 g, in 90% yield).

Example 1.2.3

N-(4″-bromo-[1,1′:4′,1″-terphenyl]-4-yl)-N-phenylnaphthalen-1-amine (8)

A mixture of compound 7 (4.5 g, 9.0 mmol), 1-bromo-4-iodobenzene (5.12g, 18 mmol), Pd(PPh₃)₄ (0.52 g, 0.45 mmol) and potassium carbonate(4.436 g, 32 mmol) in dioxane/water (150 ml/30 ml) was degassed andheated at 95° C. overnight. After being cooled to RT, the mixture waspoured into dichloromethane (300 ml), washed with brine, dried overNa₂SO₄, then loaded on silica gel, purified by flash column (hexanes tohexanes/ethyl acetate 20:1) to give a light yellow solid 8 (4.30 g, in90.7 yield).

Example 1.2.4

Host-1:

A mixture of compound 8 (1.50 g, 2.47 mmol), compound 5 (1.11 g, 2.35mmol), Pd(PPh₃)₄ (0.16 g, 0.14 mmol) and potassium carbonate (1.38 g, 10mmol) in dioxane/water (60 ml/10 ml) was degassed and heated at 85° C.for 18 hours. After being cooled to RT, the mixture was filtered. Thesolid and the filtrate were collected separately. The solid from thefirst filtration was redissolved in dichloromethane (100 ml), loaded onsilica gel, and purified by flash column (dichloromethane todichloromethane/ethyl acetate 9:1) to collect the desired fraction,concentrated. The white precipitate was filtered and dried in air togive a light yellow solid, Host-1 (1.35 g). The overall yield is 73%.LCMS data: calcd for C₅₉H₄₂N₃ (M+H): 792.3. found m/e=792.

8-2. Example of OLED Device Configuration and Performance Example 2.1(Device-A)—Fabrication of Light-Emitting Device

A device (Device A) was fabricated in a manner similar to the following.The ITO substrates having sheet resistance of about 14 ohm/sq werecleaned ultrasonically and sequentially in detergent, water, acetone,and then isopropyl alcohol (IPA); and then dried in an oven at 80° C.for about 30 min under an ambient environment. Substrates were thenbaked at about 200° C. for about 1 hour in an ambient environment, thenunder UV-ozone treatment for about 30 minutes. PEDOT:PSS (hole-injectionmaterial) was then spin-coated on the annealed substrate at about 4000rpm for about 30 sec. The coated layer was then baked at about 100° C.for 30 min in an ambient environment, followed by baking at 200° C. for30 min inside a glove box (N₂ environment). The substrate was thentransferred into a vacuum chamber, where4,4′-bis[N-(naphthalenyl)-N-phenyl-amino]biphenyl (NPB) was vacuumdeposited at a rate of about 0.1 nm/s rate under a base pressure ofabout 2×10⁻⁷ torr.Bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (“Ir(piq)₂acac”)(6 wt %) was co-deposited as an light-emitting layer with Host-1 hostmaterial at about 0.01 nm/s and about 0.10 nm/s, respectively, to makethe appropriate thickness ratio.

1,3,5-Tris(1-phenyl-1H-benzimidazol-)-2-yl)benzene (TPBI) was thendeposited at about 0.1 nm/s rate on the light-emitting layer. A layer oflithium fluoride (LiF) (electron injection material) was deposited atabout 0.005 nm/s rate followed by deposition of the cathode as Aluminium(Al) at about 0.3 nm/s rate. The representative device structure was:ITO (about 150 nm thick)/PEDOT:PSS (about 30 nm thick)/NPB (about 40 nmthick)/Host-1: Ir(piq)₂acac (about 30 nm thick)/TPBI (about 30 nmthick)/LiF(about 0.5 nm thick)/Al (about 120 nm thick). The device wasthen encapsulated with a getter attached glass cap to cover thelight-emitting area of the OLED device in order to protect frommoisture, oxidation or mechanical damage.

Each individual device had an area of about 13.2 mm².

Example 3 Device Performance Example 3.1

All spectra were measured with a PR670 spectroradiometer (PhotoResearch, Inc., Chatsworth, Calif., USA), and I-V-L characteristics weretaken with a Keithley 2612 SourceMeter (Keithley Instruments, Inc.,Cleveland, Ohio, USA). All device operation was performed inside anitrogen-filled glove-box. Device A, a red light emitting device,comprising Host-1: Ir(piq)₂acac and fabricated in accordance withExample 2.1, was tested to determine the emissive qualities of thedevice by examining the current density and luminance as a function ofthe driving voltage, as shown in FIG. 2. The turn-on voltage for thedevice was about 2.5 volts and the luminance was about 8,000 cd/m² with13.2 mm² area device at about 6V.

TABLE 1 Device PE (Lm/w) LE (cd/A) Device A 9.8 10.4

Thus Compound Host-1 has demonstrated its effectiveness as a hostmaterial in organic light emitting devices.

Example 3.2

Device A, a light emitting device comprising Host-1: Ir(piq)₂acac, andfabricated in accordance with Example 2.1, was tested to determine thelifetime of the devices (T₅₀(h) at 10,000 nit). Other devices(Comparative Device X [Bebq2], and Comparative Device Y [CBP]) wereconstructed in accordance to Example 2.1, except that, for therespective

devices, Comparative Compound X,Bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq₂ (94%), andBis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (“Ir(piq)₂acac”)(6%), and Comparative Compound Y, 4,4′-bis(carbazol-9-yl)biphenylCBP(94%), and Bis(1-phenylisoquinoline)(acetylacetonate)iridium(III)(“Ir(piq)₂acac”) (6%) were co-deposited on top of NPB, respectively, toform a 30 nm thick light-emitting layer 20.

All spectra were measured with an PR670 spectroradiometer (PhotoResearch, Inc., Chatsworth, Calif., USA) (and I-V-L characteristics weretaken with a Keithley 2612 SourceMeter (Keithley Instruments, Inc.,Cleveland, Ohio, USA). All device operation was performed inside anitrogen-filled glove-box without encapsulation.

Table 2 shows the device lifetime of devices fabricated in accordance toExamples 2.2 and 2.3.

Device T50(h) @ 10000 nit Device A 200 Comparative Device X 100Comparative Device Y 6

Thus at least Host-1 has demonstrated its effectiveness as a longlasting compound in light emitting organic light emitting devices.

Although the claims have been described in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the scope of the claims extend beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses and obvious modifications and equivalents thereof.

What is claimed is:
 1. A compound represented by a formula:


2. A light-emitting device comprising a compound of claim
 1. 3. Thelight-emitting device of claim 2, wherein the compound is in alight-emitting layer.